The Geysers-Clear Lake geothermal area, California - An updated geophysical perspective of heat sources
W. D. Stanley, R.J. Blakely
1995, Geothermics (24) 187-221
The Geysers-Clear Lake geothermal area encompasses a large dry-steam production area in The Geysers field and a documented high-temperature, high-pressure, water-dominated system in the area largely south of Clear Lake, which has not been developed. Both systems have been extensively studied with geophysical techniques, drilling, and geological mapping during the...
Tilting history of the San Manuel-Kalamazoo porphyry system, southeastern Arizona
E. R. Force, W.R. Dickinson, J.T. Hagstrum
1995, Economic Geology (90) 67-80
The Laramide San Manuel-Kalamazoo porphyry system of Arizona has been pivotal in concepts of both extensional tectonics and alteration-mineralization zoning. This paper reexamines the tilting history in light of new work in the region and reinterprets the geometry of the deposit. The porphyry mineralization occurs in and near an intrusion...
Relations between winter atmospheric circulation and annual streamflow in the western United States
G. J. McCabe Jr.
1995, Climate Research (5) 139-148
Winter mean 700 millibar (700 mb) height anomalies, representing the average atmospheric circulation during the snow season, were compared with annual streamflow measured at 140 stream gauges in the western United States. Correlation analysis was used to identify relations between winter mean atmospheric circulation and annual streamflow, and to quantify...
Cooling, degassing and compaction of rhyolitic ash flow tuffs: A computational model
J.R. Riehle, T.F. Miller, R. A. Bailey
1995, Bulletin of Volcanology (57) 319-336
Previous models of degassing, cooling and compaction of rhyolitic ash flow deposits are combined in a single computational model that runs on a personal computer. The model applies to a broader range of initial and boundary conditions than Riehle's earlier model, which did not integrate heat and mass flux with...
Algorithm for resistance to flow and transport in sand-bed channels
J. P. Bennett
1995, Journal of Hydraulic Engineering (121) 578-590
An algorithm is developed that relates depth to discharge and determines bed- and suspended-load transport for the entire range of bed forms found in sand-bed channels; equilibrium-state geometry of lower flow regime bedforms is also predicted. A Meyer-Peter-type formulation is used to compute sand transport in the bed-load layer and...
Geology of epithermal silver-gold bulk-mining targets, bodie district, Mono County, California
V.F. Hollister, M.L. Silberman
1995, Nonrenewable Resources (4) 129-137
The Bodie mining district in Mono County, California, is zoned with a core polymetallic-quartz vein system and silver- and gold-bearing quartz-adularia veins north and south of the core. The veins formed as a result of repeated normal faulting during doming shortly after extrusion of felsic flows and tuffs, and the...
Pesticides in near-surface aquifers: An assessment using highly sensitive analytical methods and tritium
D.W. Kolpin, D. A. Goolsby, E.M. Thurman
1995, Journal of Environmental Quality (24) 1125-1132
In 1992, the U.S. Geological Survey (USGS) determined the distribution of pesticides in near-surface aquifers of the midwestern USA to be much more widespread than originally determined during a 1991 USGS study. The frequency of pesticide detection increased from 28.4% during the 1991 study to 59.0% during the 1992 study....
Zinc, copper, and lead geochemistry of oceanic igneous rocks - ridges, islands, and arcs
B. R. Doe
1995, International Geology Review (37) 379-420
Variations in the abundances of Zn, Cu, and Pb are found to be useful in identifying tectonic regimes and separating oceanisland basalts into enriched- and depleted-source categories. The average Zn, Cu, and Pb contents of normal mid-ocean ridge basalts (N-MORB) are 84, 70, and 0.35 ppm, respectively. Differences in...
Chemical and isotopic evolution of a layered eastern U.S. snowpack and its relation to stream-water composition
J. B. Shanley, C. Kendall, M.R. Albert, J.P. Hardy
1995, Biogeochemistry of seasonally snow-covered catchments. Proc. symposium, Boulder, 1995 (228) 329-338
The chemical, isotopic, and morphologic evolution of a layered snowpack was investigated during the winter of 1993-94 at Sleepers River Research Watershed in Danville, Vermont. The snowpack was monitored at two small basins: a forested basin at 525 m elevation, and an agricultural basin at 292 m elevation. At each...
Role of near-bed turbulence in bedload transport
Jonathan M. Nelson, Ronald L. Shreve, Stephen R. McLean
1995, Conference Paper, Proceedings of Engineering Mechanics
Bedload transport by a turbulent fluid moving over an erodible sediment bed results from complex interactions between flow field of the overlying fluid and the grains making up the bed. To develop a better view of these interactions, a method that combines high-speed photography with laser-Doppler velocimetry was devised. The...
Fish communities
K. D. Lafferty, J.A. Altstatt
R.F. Ambrose, editor(s)
1995, Report
No abstract available at this time...
Digestive performance of the desert tortoise (Gopherus agassizii) fed native and non-native desert vegetation. Final Report to California Department of Parks and Recreation, Off-Highway Motor Vehicle Recreation Division, Sacramento, California
H.W. Avery
1995, Report
No abstract available at this time...
Invertebrate communities
C.P. Sandoval, K. D. Lafferty
R.F. Ambrose, editor(s)
1995, Report
No abstract available at this time...
Simulation models for conservative and nonconservative solute transport in streams
R.L. Runkel
1995, Effects of scale on interpretation and management of sediment and water quality. Proc. symposium, Boulder, 1995 (226) 153-159
Solute transport in streams is governed by a suite of hydrologic and chemical processes. Interactions between hydrologic processes and chemical reactions may be quantified through a combination of field-scale experimentation and simulation modeling. Two mathematical models that simulate conservative and nonconservative solute transport in streams are presented. A model for...
Scale as a factor in designing sampling programs for determination of annual trace element fluxes
A. J. Horowitz
1995, Effects of scale on interpretation and management of sediment and water quality. Proc. symposium, Boulder, 1995 (226) 293-301
Concentration data of suspended sediment-associated trace elements are a requisite for estimation of annual chemical fluxes. Fluvial suspended sediment and associated trace elements display marked shortterm spatial and temporal variability, suggesting that determination of annual fluxes requires high frequency depth and width integrated sampling and subsequent chemical analyses. When time...
Identifying trends in sediment discharge from alterations in upstream land use
R. S. Parker, W. R. Osterkamp
1995, Effects of scale on interpretation and management of sediment and water quality. Proc. symposium, Boulder, 1995 (226) 207-213
Environmental monitoring is a primary reason for collecting sediment data. One emphasis of this monitoring is identification of trends in suspended sediment discharge. A stochastic equation was used to generate time series of annual suspended sediment discharges using statistics from gaging stations with drainage areas between 1606 and 1 805...
Regional mapping of karst terrains in order to avoid potential environmental problems
K.S. Johnson, J.F. Quinlan
1995, Cave and Karst Science - Transactions British Cave Research Association (21) 37-39
The oklahoma Geological Survey will prepare a map of the State at a scale of 1:500,000 to show karst terrains and associated environmental problems in Oklahoma. Surface and near-surface carbonates (limestone and dolomite) comprise about 6% of the surface area of the State, whereas sulphates (gypsum and anhydrite) comprise about...
The effect of surface anisotropy and viewing geometry on the estimation of NDVI from AVHRR
David Meyer, M. Verstraete, B. Pinty
1995, Remote Sensing Reviews (12) 3-27
Since terrestrial surfaces are anisotropic, all spectral reflectance measurements obtained with a small instantaneous field of view instrument are specific to these angular conditions, and the value of the corresponding NDVI, computed from these bidirectional reflectances, is relative to the particular geometry of illumination and viewing at the time of...
The chemical and hydrologic structure of Poas volcano, Costa Rica
G.L. Rowe Jr., S.L. Brantley, J.F. Fernandez, A. Borgia
1995, Journal of Volcanology and Geothermal Research (64) 233-267
Comparison of the chemical characteristics of spring and river water draining the flanks of Poas Volcano, Costa Rica indicates that acid chloride sulfate springs of the northwestern flank of the volcano are derived by leakage and mixing of acid brines formed in the summit hydrothermal system with dilute flank groundwater....
A summary of the effects of mining and related activities on the sediment-trace element geochemistry of Lake Coeur d'Alene, Idaho, USA
A. J. Horowitz, K. A. Elrick, J. A. Robbins, R.B. Cook
1995, Journal of Geochemical Exploration (52) 135-144
During 1989 and 1990 a series of 12 gravity cores, and 150 surface grab samples were collected in Lake Coeur d'Alene, Idaho to determine trace element concentrations, partitioning and surface and subsurface distribution patterns in the bed sediments of the lake....
Thermodynamics of gas and steam-blast eruptions
L.G. Mastin
1995, Bulletin of Volcanology (57) 85-98
Eruptions of gas or steam and non-juvenile debris are common in volcanic and hydrothermal areas. From reports of non-juvenile eruptions or eruptive sequences world-wide, at least three types (or end-members) can be identified: (1) those involving rock and liquid water initially at boiling-point temperatures (‘boiling-point eruptions’); (2) those powered...
Population status of the mountain yellow-legged frog (Rana muscosa) in the Angeles National Forest. Final report prepared for the United States Department of Agriculture, Angeles National Forest, Arcadia, California, through Interagency Agreement (5-01-69-019)
M.R. Jennings
1995, Report
No abstract available at this time...
Bird communities
K. D. Lafferty
R.F. Ambrose, editor(s)
1995, Report
No abstract available at this time...
Optimization techniques for integrating spatial data
U.C. Herzfeld, D. F. Merriam
1995, Mathematical Geology (27) 559-588
Two optimization techniques ta predict a spatial variable from any number of related spatial variables are presented. The applicability of the two different methods for petroleum-resource assessment is tested in a mature oil province of the Midcontinent (USA). The information on petroleum productivity, usually not directly accessible, is related indirectly...
Use of electric logs to estimate water quality of pre-tertiary aquifers
J. B. Lindner-Lunsford, Breton W. Bruce
1995, Groundwater (33) 547-555
Electric logs provide a means of estimating ground-water quality in areas where water analyses are not available. Most of the methods for interpreting these logs have been developed for the petroleum industry and are most reliable in saline aquifers (concentration of dissolved solids as sodium...
